Effect of screw spacing on axial strength of cold-formed steel built- up box sections-numerical investigation and parametric study (original) (raw)

In cold-formed steel (CFS) structures, the use of built-up box sections are becoming increasingly popular for column members. Applications of CFS built-up box sections include in steel trusses, space frames, and portal frames. This paper considers the finite element modelling of built-up CFS box sections under axial compression. The FE models considered nonlinear material properties, initial imperfections and modeling of intermediate fasteners. The FE results showed good agreement against the laboratory test results reported in other study for such CFS builtup box sections. The validated FE model was then used to conduct a parametric study comprising 148 models. The effect of screw spacing on the axial capacity, was investigated. Both the finite element and laboratory test results were compared against the design strengths calculated in accordance with the American Iron and Steel Institute (AISI) and Australian and New Zealand Standards (AS/NZS). From the comparison, it was observed...